Guiding device for picked weft threads

ABSTRACT

Pneumatically picked weft threads are guided by a row of alternating first and second guide members which have aligned guide openings having outlet gaps which are angularly staggered so that the outlet gap of each guide member is crossed by a portion of an adjacent guide member. In this picking position, the guide openings form a guide passage which is substantially closed about the periphery thereof. When the guide members are moved out of the warp shed, the warp threads retain the picked weft thread in the warp shed, and the weft thread passes successively through the rows of outlet gaps of alternate guide members.

C United States Patent 1111 7, 4

[72] Inventors Vladimir Svaty; [56] References Cited Jiri Libansky. Liberec. Czechoslovakia UNITED STATES PATENTS P 839,452 741,749 10/1903 Wattie 139/128 ggf f' 22:33 3,203,452 8/1965 Svaty.. 139 127 [73] Assignee Elitex-Zavody Textilniho Strojire 3,399,701 9/1968 TeStrake 139/127 Generalini Reditelstvi Primary Examiner-Henry S. Jaudon Liberec, Czechoslovakia Atl0mey-Michael S. Striker [32} Priority July 4, 1968 [3 3] Czechoslovakia [3 1 1 pv4913 68 ABSTRACT: Pneumatically plcked weft threads are guided by a row of alternating first and second guide members which have aligned guide openings having outlet gaps which are an- 1 GUIDING DEVICE FOR PICKED WEFT THREADS gularly staggered so that the outlet gap of each guide member 12 Cl 6 D is crossed by a portion of an adjacent guide member. In this rawmg picking position, the guide openings form a guide passage [52] US. Cl 139/127, which is substantially closed about the periphery thereof.

139/188, 191 When the guide members are moved out of the warp shed, the

[51] Int. Cl D03d 47/30 warp threads retain the picked weft thread in the warp shed,

[50] Field of Search 139/122, 1, and the weft thread passes successively through the rows of outlet gaps of alternate guide members.

GUIDING DEVICE FOR PICKED WEFT THREADS BACKGROUND OF THE INVENTION The present invention relates to a guiding device for guiding picked wefts, particularly suited for a pneumatic loom in which the weft is picked and inserted into a warp shed by a stream of air. Known pneumatic looms have the disadvantage that the stream of air blown through the warp shed does not have sufficient power to carry an entrained weft thread a very great distance. The friction encountered by the stream of air in the surrounding air causes turbulence so that the stream widens, its flow velocity drops, and the flow of air in the stream becomes irregular. Due to this reason, the picked weft thread is frequently caught by a warp yarn, and the weft is not inserted through the whole width of the warp shed. In known looms of this type, the length of an inserted weft thread cannot be greater than 0.5 meters.

It has been proposed to guide the stream of air by guide members which form a comblike structure with guide recesses. The guide recesses have to be open on one side to permit the removal of the picked weft thread from the guide structure. Therefore, the stream of air is not fully confined in the guide structure, but nevertheless the length of the weft can be increased substantially. Due to the fact that the air escapes on the open sides of the guide recesses, or through gaps in the guide members, the flow velocity of the stream of air is reduced after a certain picking length. Since the open sides of the recesses, or outlet gaps of guide openings are aligned, the weft thread is sometimes blown out of the aligned outlet gaps and not properly picked through the entire warp shed. Pneumatic looms of this type are disclosed in the US. Pat. Nos. 3,065,770 and 3,139,118.

SUMMARY OF THE INVENTION It is one object of the invention to overcome the disadvantages of known guiding devices for picked weft threads, and to provide a guide passage in the warp shed from which substantially no air can laterally escape.

Another object of the invention is to increase the length of a weft thread which can be picked by an air stream of predetermined velocity.

Another object of the invention is to provide a small and compact guiding device for picked weft threads which is movable between a picking position located in a warp shed, and a beating position located outside of the warp shed so that the reed can beat up the picked and inserted weft thread.

Another object of the invention is to provide a guide passage for a picked weft which is substantially closed in peripheral direction so that the weft thread cannot laterally escape.

With these objects in view, the present invention provides a guiding device for picked weft threads, particularly for weft threads picked by a stream of air produced by a noule in a pneumatic loom.

One embodiment of the guiding device comprises a row of first guide members and a row of second guide members alternating with the first guide members, and each guide member being formed with a guide opening and with an outlet gap for the guide opening. The first and second guide members have a picking position in which the guide openings are aligned and form a passage for a picked weft, while the outlet gap of each guide member is crossed by portions of the respective adjacent guide member. As a result, the passage through which the weft is picked, is substantially closed about the periphery thereof, and an escape of the picked weft thread through the outlet gaps is not possible.

On the other hand, when the first and second guide members are successively moved out of the warp shed, the warp threads, passing between alternate guide members, retain the weft thread which moves out of the guide openings through the aligned outlet gaps.

In the preferred embodiment of the invention, a row of first guide members has first guide portions formed with first guide openings aligned along an axis, and having first end portions forming first aligned outlet gaps for the first guide openings, respectively; a row of second guide members alternating with the first guide members and having second guide portions formed with second guide openings along an axis. and having second end portions forming second aligned outlet gaps for the second guide openings; and operating means for moving the first and second guide members between a picking position located between warp threads, and beating positions located outside of the warp shed.

In the picking position, the first and second guide portions are aligned in a warp shed along the coinciding axes while the first and second outlet gaps are angularly spaced from each other about the coinciding axes, and the guide portions extend across the outlet gaps of adjacent guide members. As a result. the first and second guide openings form in the warp shed a passage for a picked weft, and the passage is substantially closed about the periphery due to the angular staggering of the outlet gaps. In the beating position, the first and second guide portions are located spaced from each other and outside of the warp shed, while the picked weft thread remains in the warp shed after passing through the first aligned outlet gaps, and then through the second aligned outlet gaps when the second outlet gaps cross the warp threads on which the picked weft thread lies.

The operating means comprise slay means supporting the second guide members, and linkage means connecting the first guide members with the slay means for moving the first guide members in timed relation with the second guide members between the picking and beating positions.

The first and second guide members preferably have arms with confronting recesses for receiving warp threads extend ing between adjacent first and second guide members in the picking position. It is advantageous to provide the arms of first and second adjacent guide members with wedge-shaped cross sections disposed in opposite directions so that sufficient space for a warp thread is left between the arms of adjacent guide members.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a fragmentary elevation, partially in section, illustrating a pneumatic loom provided with the guiding device of the invention in a position in which a weft is picked;

FIG. 2 is an elevation, partially in section, illustrating another operational position of the guiding device after picking of a weft thread and before the beating up of the picked weft thread;

FIG. 3 is a fragmentary front elevation, partially in section, and illustrating the apparatus of FIG. 1 as viewed in the direction of the arrow III;

FIG. 4 is a fragmentary sectional view taken along line rv-rv in FIG. 1;

FIG. 5a is a fragmentary horizontal sectional view illustrating modified guide members in the picking position, and on an enlarged scale; and

FIG. Sb is a fragmentary horizontal sectional view corresponding to FIG. 5a but illustrating a different position of the guide members.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A rockable slay has arms 2 mounted for angular movement on a shaft 1, and a batten 7 secured to the upper ends of arms 2 by screws 4. A reed 8 is mounted on batten 7 by means of screws 3a, and a pivot 6 connects at least one arm 2 with a link driven by a cam follower from an eccentric cam on a cam shaft, not shown, so that slay 2, 7 'rocks with the reed 8 between the rear position substantially shown in FIG. 1, and a beat up position, now not shown, in which the reed 8 is disposed at the fell 33a of the fabric 33 which is woven of two warps 27 and 28 consisting of warp threads, and of weft threads 32 inserted into the warp shed by a nozzle 30 to which pressure air is supplied by a tube 31, as shown in FIG. 3.

The batten 7 has a row of slots 10 into which a series of guide members 9 is inserted and adhesively attached by an epoxy glue so that the guide member 9 fonns a comblike structure. Each guide member 9 has a guide portion 12 forming a guide opening 12a which is connected with an outlet gap 14 formed by the two ends of guide portion 12, the end portion 16 being longer and projecting upward. All guide openings 12a are aligned along an axis, and the outlet gaps 14 are also aligned. In the rear dead center position of the slay 2, 7, shown in FIG. 2, the passage formed by the guide 1212 a is located in the warp shed aligned with the noule 30, as best seen in FIG. 3, while the outlet gaps 14 are aligned to permit a weft located in the aligned guide openings 12a to move out of the same. A row of guide members 11 alternates with guide members 9, as best seen in FIG. 2. Guide members 11 have arms 11a with hubs fixedly secured to a shaft 3 which is mounted for turning movement on the batten 7 and passes through openings 3a in guide members 9.

At the outer ends of arms 11, guide portions 13 are provided which form central guide openings 13 a aligned along an axis. An outlet gap connects each guide opening 13a with the outside of guide portion 13. In the picking position of FIG. 1 and FIG. 3, guide portions 13 and 12 of guide members 11 and 9 are aligned, so that the axes of the guide openings 13a and 12a coincide, and the alternating guide openings 12a and 1311 form a guide passage. The outlet gaps 14 and 15 are ang'ularly staggered in the picking position, outlet gaps 14 being substantially vertical, and outlet gaps 15 being substantially horizontal. Consequently, in the picking position of FIG. 1, parts of each guide portion 13 extend across the outlet gaps 14 of adjacent guide members 9, and parts of guide portions 12 extend across outlet gaps 15 of adjacent guide members 11 so that the guide passage 29 formed by alternating guide openings 12a and 13a is substantially closed, and a stream of air blown out of nozzle 30 in axial direction of the aligned guide openings 12a and 13a, blows a weft thread 32 through the guide passage while being confined in the same since the outlet gaps are substantially closed. I

A lever arm 17 is secured to shaft 3 and turns with the same and with all guide members 11. A link 19 is connected by pivot 18 with lever 17 and by pivot 20 with the arm 21 of an angular lever which is mounted on a stationary shaft 22 and has another arm 23 connected by a pivot 24 to a link 25 connected by a pivot 26 with the slay 2.

When the slay rocks in clockwise direction from the position of FIG. 1 to the position of FIG. 2, the row of guide members 9 is displaced, and at the same time, the linkage 17 to 26 and 3 is displaced so that guide members 11 perform an angular movement with shaft 3 relative to guide members 9. However, the kinematics of linkage 17 to 26 do not cause a substantial relative displacement between the guide members 9 and 11 in the region of the rear dead center position of the slay.

In the position shown in FIGS. 1, the slay 2, 7 is near the rear dead center position, and due to the construction of the linkage 17 to 26, the guide portions 12, 13 and the guide openings 12a, Ba are aligned along an axis with the air nozzle 30 to which a weft thread 32 is supplied through a central axial duct, as shown in FIG. 3. Pressure air is supplied through tube 31 to nozzle 30, and the weft thread 32 is blown through the passage formed by guide openings 12a and 13a. Since the outlet gaps 15 and 13 are crossed by parts of the adjacent guide portions, of the respective adjacent guide members, no substantial air losses occur through the outlet gaps, and the full force of the stream of air is effective to carry the entrained weft thread across the loom and through the entire width of the warp shed.

During the picking of the weft thread 32 by a stream of air, the two rows of alternating guide portions l2, 13 remain in the picking position shown in FIG. 1', although the slay 2, 7 may first approach its dead center position, and then move again out of the dead center position. This is due to the construction of the linkage 17 to 26 in which pivots 22, 20 and 18, and arm 21 and link 19 are aligned and extend substantially at right angles to arm 17 while the slay is in the region of the dead center position shown in FIG. 1. Consequently, there issufficient time available for the picking of the weft thread through the guide passage 29 formed in the picking position shown in FIG. 1 by the guide portions 12 and 13.

When the weft thread has been picked, and slay 2, 7 continues its clockwise movement toward the beat up position, the linkage 17 to 26 gradually assumes the position shown in FIG. 2 and due to the displacement of the linkage, the row of guide members 11 moves with shaft 3 relative to the row of alternate guide members 9 to the position of FIG. 2.

Since during such movement, the aligned outlet gaps 15 in the guide portions 13 trail in the direction of movement of guide portion 13, the weft thread remains in passage formed by the row of guide openings 12a formed in guide portions 12 of guide members 9, and easily passes through the aligned outlet gaps 15 which together form an outlet channel for the portion of weft thread 32 which was during the picking located also in the guide openings 13a.

During further angular movement of slay 2, 7 in clockwise direction, the row of guide portions l3 passes through the warp thread of the lower warp 28 so that guide portions 13 no longer obstruct the warp shed. Further movement of the slay 2, 7 brings guide members 9 to a position in which the warp threads of the lower warp 28 are passed by the outlet gaps 14 in guide portions 12 so that the weft thread located in the row of aligned guide openings 12a of guide members 9, is retained by the warp threads, and guide members 9 can move to an inoperative position located below the warp shed so that the same is free for the further movement of reed 8 to a beat up position, not shown, for beating the inserted weft thread into the fell 33a of the fabric '33. In this beating position, all guide portions 12 and 13 are located below the warp shed after having left the picked weft thread 32 in the warp shed.

While in the picking position of FIG. I, the aligned guide openings 12a and 13a are substantially peripherally closed by adjacent guide portions to form a passage for the stream of air picking the weft thread, in the intermediate position of FIG. 2, the outlet gaps 15 and 14 are no longer closed, so that the outlet gaps are open, and the weft thread can be first moved removed from guide portions 13 and then from guide portions 12, as described above. I

After the beating of the weft thread has been carried out by the reed 8, the slay 2, 7-reverses its movement and moves toward the intermediate position shown in FIG. 2 and the picking position shown in FIG. 1. At first, when all guide portions 12 and '13 are located below the warp shed 28, the .pro-

jecting end portions 16 of the guide members 9 enter between adjacent warp threads of warp 28 so that the guide portions 12 gradually enter the warp shed,and during further movement of the slay, the guide portions 13 enter between adjacent warp threads into the warp shed'in the position shown in FIG. 2. Due to the kinematics of linkage 17 to 26, guide members 11 begin to move faster, and when the slay is in the rear dead center position shown in FIG '1, the guide openings 12a and 13a are aligned so that the next picking operation can take place.

As shown in FIG. 1, the warp threads of the lower warp 28 extend between the arms 1 1a and 9a of guide members Hand 9, and in order to provide more room for the warp threads, the lateral faces of arms 9a and 11a have recesses 36 and 37 disposed to receive the lower warp threads, as best seen in FIGS. 1 and 3.

In the embodiment of FlGS. 1-4, the arms 9a and 11a are spaced from each other when the guide portions 13 and 14 are aligned, so that different portions of the lower warp threads engage arms 11a and 9a, and clamping of warp threads is reliably prevented.

In the modified embodiment of FIGS. 5a and 5b, the arms 90 and 110, have wedge-shaped cross sections disposed in opposite directions so that gaps having a substantially uniform width S1 are formed by adjacent arms 9a and 11a through which the warp threads can pass in the picking position shown in FIG. 5a. 1n the position of FIG. Sb,corresponding to the position of FIG. 2, the space between adjacent arms 9a and 11a is increased to the larger distance 52 which is the advantage of the wedge-shaped cross section.

It will be seen that due to the closing of the outlet gaps in the picking position of guide members 9 and 11, a more reliable insertion of the picked wefts into the warp sheds is obtained so that weft threads of greater length can be used, and the cross section of the guide openings 12a and l3a,and thereby the size of the guide portions 12 and 13 can be reduced. This has the advantage that a smaller amount of pressure air is required for the picking of the weft thread, than in prior art constructions. The more accurate confinement of the stream of air, permits also the use of very fine threads without disturbances of the operations of the loom.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of looms differing from the types described above.

While the invention has been illustrated and described as embodied in a guiding device for weft threads picked by a stream of air, including first and second alternating guide members together forming a guide passage, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims.

We claim:

1. Guiding device for picked weft threads comprising, in combination, a row of first guide members, and a row of second guide members alternately arranged relative to said first guide members, each said guide member being fonned with a guide opening and with an outlet gap communicating with said guide opening, said first and second guide members having a picking position in which said guide openings are aligned to form a passage for a picked weft while the outlet gap of each guide member is crossed by portions of the respective adjacent guide members so that said passage is substantially closed along said periphery thereof.

2. Guiding device as claimed in claim 1 comprising a pneumatic nozzle aligned with said guide openings and for blowing a weft thread through said guide passage while said first and second guide members are in said picking position.

3. Guiding device as claimed in claim 1 wherein said passage of aligned guide openings is located in a warp shed; with said guide members alternately passing between adjacent warp threads when said picked weft thread is received therethrough; and comprising means for moving said rows of first and second guide members successively out of said warp shed so that said first and second guide members release the picked weft thread through said outlet gaps into the warp shed.

4. Guiding device as claimed in claim 3 wherein said outlet gaps of said first guide members trail said guide openings in the direction of movement of said first guide members out of said warp shed so that the picked weft thread retained by said second guide members passes through said outlet gaps of said first guide members.

5. Guiding device as claimed in claim 1 wherein all said guide openings are in said picking position aligned along an axis; and wherein in said picking position said outlet gaps of adjacent guide members are angularly staggered about said axis.

6. Guiding device as claimed in claim 1 wherein said first and second guide members have wedge-shaped cross sections disposed in opposite directions.

7. Guiding device as claimed in claim 1 wherein said guide openings are in said picking position located in a warp shed; wherein said first and second guide members alternately pass between warp threads; and wherein said first and second guide members have recesses for receiving said warp threads in said picking position.

8. Guiding device for picked weft threads, comprising, in combination, a row of first guide members having first guide portions formed with first guide openings aligned along an axis, and having first end portions forming first aligned outlet gaps for said first guide openings, respectively; a row of second guide members alternately arranged relative to said first guide members and having second guide portions formed with second guide openings aligned along an axis, and having second end portions forming second aligned outlet gaps for said second guide openings; and operating means for moving said first and second guide members between a picking position located between warp threads, inwhich picking position said first and second guide portions are aligned in a warp shed along said axes which coincide, while said first and second outlet gaps are angularly spaced from each other about said coinciding axes and said guide portions extend across said outlet gaps of adjacent guide members, respectively, whereby said first and second guide openings form in said warp shed a passage for a picked weft substantially closed about the periphery thereof, and beating positions in which said first and second guide portions are located outside of the warp shed while the picked weft thread remains in the warp shed after passing successively through said first aligned outlet gaps and said second aligned outlet gaps.

9. Guiding device as claimed in claim 8 wherein said operating means comprise rockable slay means supporting said second guide members for movement between said picking and beating positions, and linkage means connecting said first guide members with said slay means for moving said first guide members in timed relation with said second guide members between said picking and beating positions so that first said first guide members and then said second guide members assume said beating positions thereof located outside of the warp shed.

10. Guiding device as claimed in claim 9 wherein said linkage means include a shaft turnably mounted on said slay means and fixedly supporting said first guide members, said second guide members having aligned openings through which said shaft passes, and a linkage connecting said shaft with said slay means and including at least one stationary pivot so that said shaft with said first guide members turns relative to said second guide members during movement of said slay means.

11. Guiding device as claimed in claim 8 wherein said first and second guide members have arms, respectively, at whose ends said first and second guide portions are located, respectively; and wherein said arms have recesses for receiving warp threads extending between adjacent arms of said first and second guide members in said picking position.

12. Guiding device as claimed in claim 11 wherein said arms of said first and second guide members have wedge-shaped cross sections disposed in opposite-directions. 

1. Guiding device fOr picked weft threads comprising, in combination, a row of first guide members, and a row of second guide members alternately arranged relative to said first guide members, each said guide member being formed with a guide opening and with an outlet gap communicating with said guide opening, said first and second guide members having a picking position in which said guide openings are aligned to form a passage for a picked weft while the outlet gap of each guide member is crossed by portions of the respective adjacent guide members so that said passage is substantially closed along said periphery thereof.
 2. Guiding device as claimed in claim 1 comprising a pneumatic nozzle aligned with said guide openings and for blowing a weft thread through said guide passage while said first and second guide members are in said picking position.
 3. Guiding device as claimed in claim 1 wherein said passage of aligned guide openings is located in a warp shed; with said guide members alternately passing between adjacent warp threads when said picked weft thread is received therethrough; and comprising means for moving said rows of first and second guide members successively out of said warp shed so that said first and second guide members release the picked weft thread through said outlet gaps into the warp shed.
 4. Guiding device as claimed in claim 3 wherein said outlet gaps of said first guide members trail said guide openings in the direction of movement of said first guide members out of said warp shed so that the picked weft thread retained by said second guide members passes through said outlet gaps of said first guide members.
 5. Guiding device as claimed in claim 1 wherein all said guide openings are in said picking position aligned along an axis; and wherein in said picking position said outlet gaps of adjacent guide members are angularly staggered about said axis.
 6. Guiding device as claimed in claim 1 wherein said first and second guide members have wedge-shaped cross sections disposed in opposite directions.
 7. Guiding device as claimed in claim 1 wherein said guide openings are in said picking position located in a warp shed; wherein said first and second guide members alternately pass between warp threads; and wherein said first and second guide members have recesses for receiving said warp threads in said picking position.
 8. Guiding device for picked weft threads, comprising, in combination, a row of first guide members having first guide portions formed with first guide openings aligned along an axis, and having first end portions forming first aligned outlet gaps for said first guide openings, respectively; a row of second guide members alternately arranged relative to said first guide members and having second guide portions formed with second guide openings aligned along an axis, and having second end portions forming second aligned outlet gaps for said second guide openings; and operating means for moving said first and second guide members between a picking position located between warp threads, in which picking position said first and second guide portions are aligned in a warp shed along said axes which coincide, while said first and second outlet gaps are angularly spaced from each other about said coinciding axes and said guide portions extend across said outlet gaps of adjacent guide members, respectively, whereby said first and second guide openings form in said warp shed a passage for a picked weft substantially closed about the periphery thereof, and beating positions in which said first and second guide portions are located outside of the warp shed while the picked weft thread remains in the warp shed after passing successively through said first aligned outlet gaps and said second aligned outlet gaps.
 9. Guiding device as claimed in claim 8 wherein said operating means comprise rockable slay means supporting said second guide members for movement between said picking and beating positions, and linkage means connecting Said first guide members with said slay means for moving said first guide members in timed relation with said second guide members between said picking and beating positions so that first said first guide members and then said second guide members assume said beating positions thereof located outside of the warp shed.
 10. Guiding device as claimed in claim 9 wherein said linkage means include a shaft turnably mounted on said slay means and fixedly supporting said first guide members, said second guide members having aligned openings through which said shaft passes, and a linkage connecting said shaft with said slay means and including at least one stationary pivot so that said shaft with said first guide members turns relative to said second guide members during movement of said slay means.
 11. Guiding device as claimed in claim 8 wherein said first and second guide members have arms, respectively, at whose ends said first and second guide portions are located, respectively; and wherein said arms have recesses for receiving warp threads extending between adjacent arms of said first and second guide members in said picking position.
 12. Guiding device as claimed in claim 11 wherein said arms of said first and second guide members have wedge-shaped cross sections disposed in opposite directions. 